Kohler K-3519 Homeowner's Manual page 6

Operation (cont.)
the vessel through the screen and pressure regulator. The water then
flows across the air inducer, which mixes a small amount of air with
the water, filling the vessel until a pressure of approximately 35 psi
(2.5 Kg/cm squared) is reached. The toilet will be ready for the next
flush within 60 to 90 seconds. If the toilet is not ready for the next
flush within that time, please refer to the Troubleshooting section.
1054184-5-B 6 Kohler Co.